Electrolytic film removing apparatus



May 17, 1938. ,JHBUCHSER 2,117,294

ELECTROLYTIC FILM REMOVING APPARATUS :Filed March ll, 1956 Patented May17, 1938 UNITE STATES PATENT oFFicE ELECTROLYTIC FILM RElVIOVINGAPPARATUS 7 Claims.

(Granted under the act` of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) crease the usefulness and life ofa metallic photographic plate.

Another object of the invention is to keep in service a metallicphotographic plate, the grain of which is in good condition, withouthaving to resort to regraining the plate.

The invention set forth herein is applicable to all metal plates fromwhich it is desirable to remove a photographic image quickly and withoutinjury to the surface thereof.

Other objects of the invention will be set forth in the followingdescription which refers to the accompanying drawing. The essentialcharacteristics are summarized in the claims.

In describing the invention in detail reference is had to theaccompanying drawing, forming a part of this specification, wherein likenumerals of reference indicate corresponding parts throughout theseveral views, in which- Fig. l is a cross-sectional view of a tank,taken on line 2-2 of Fig. 2, showing plate clamping means and electricalconnections;

Fig. 2 is a top plan View of the tank shown in Fig. 1, with coverremoved;

l Fig. 3 is a diagrammatic View showing electrodes and a portion of thecircuit required in the operation of the device.

Referring to the drawing the numeral I indicates the tank and 2 thecover, which is attached thereto by means of the hinges 3. The tank isformed with an outer casing i of wood or any other suitable materialprovided with an inner lining 5 preferably of glass. The side Walls ofthe tank are constructed with opposite grooves 6 and 'I adapted for thereception of the photographic plate B which is to receive electrolytictreatment.

The inner glass lining of the tank is continued upward on the front andside walls of the tank to a comparatively short distance from the upperedge of the wooden casing, and the upper edges of these walls of thelining are thus adapted to support a glass cover plate 9 which isprovided with a slotted opening IQ, coinciding with the upper edges ofthe lateral grooves 6 and 1, and adapted for the admission of thephotographic plate 8, which functions as an electrode. The otherelectrode is indicated by the numeral II. This electrode II isconductively connected to a conduit i2 through the bolt i3 which isprovided with a wing nut I4.

Mounted on the glass cover plate 9, adjacent the front wall I5 of theouter casing 4, is fitted an elongated rectangular block I6 of wood orother suitable material, the outer upper edge of which is cut away toreceive an angularly formed strip of conducting material I1 composed ofany suitable metal. A companion block to the one just described, isdesignated by the numeral I 8. This second block I3 is provided with anangularly formed strip of conducting material I9 similar to block I5 butso fitted that the angles are positioned opposite each other. The secondblock I8 is provided with a bearing member 20 to which a link 2| ishingeably attached, the Opposite end of the link being hingeablyattached to a second bearing member 22 which is attached to thehingeably mounted tank cover 2.

From the above description of the blocks I6 and I8 and connecting link2| it will be readily seen that on closure of the cover 2 the block I8will be moved toward the block I6 and that the block I8 recedes from theblock I5 on the opening of the cover 2.

The cover 2 is also provided with a spring metal contact piece 23,provided with sharp contact points or tines 2t, said contact piece beingconductively connected to the electrical conduit 25 through the bolt 26provided with the wing nut 2l. On closure of the cover 2 the metallicphotcgraphic plate il is clamped between the blocks I5 and IS whichbring it into electrical contact with the angles Il and I9 and thecontact piece 23 which is held tightly against both the angles I l andI9 and also the plate 8, the upper edge of which extends to the level ofthe upper surfaces of said angles.

In the operation of the device, the tank is first filled with water,which is slightly acidulated to increase conductivity. The metallicphotographic plate, from which it is desirable to remove aphoto-transferred image, is then cleaned of all greasy inks which coverthe image by applying any suitable solvent now employed by the trade. Toremove the remaining albuminous photo-film the metallic photographicplate is now placed in the electrolytic bath by sliding it into thegrooves 5 and 'l where it functions as an electrode and is held parallelto the opposite electrode iI which is preferably made of zinc. 'I'heplate 8 and the opposite electrode II are retained in the electrolyte ata specified distance, ranging from one to two inches, depending upon thestrength of the electrolyte.

After the photographic plate 8 has been placed into the tank the cover 2is closed and by so doing both plates are connected in the circuit ofthe source of electric power, which is preferably 110 volts, continuousdirect current. An alternating current may be used with a rectifier orsuitable interrupter. The strength of the current is held to about .003ampere per square inch, and is permitted to ow between the plates 8 andIl for about thirty seconds, the object being to subject the plate 8 toion shock action for a fractional part of a minute. After about thirtyseconds the lid 2 of the tank l is raised and the plate 8 removed fromthe electrolyte. Plate 8 is then washed under a tap and while still wetis subjected to rubbing action which after a few minutes completelyremoves the photographic image therefrom. Acid and caustic solvents are`then applied to restore the brilliancy to the plate.

Without subjecting the plate to the electric shock, as described above,the known caustic solvents are only partially effective in removing thephotographically transferred images from metallic plates. The electriccurrent disintegrates the molecular structure and destroys the cohesionof the albuminous sensitizing compound used in making the photographictransfer onto the metallic photographic plates. In addition, theelectric ions destroy the adhesive property of the albuminous lmcomprising the image to such a degree that any caustic solvent ormechanical rubbing readily removes the transferred photographic image.

Having described my invention, what I claim as new and wish to secure byLetters Patent is:

l. A device for the electrolytic treatment of photographic platescomprising a glass lined tank provided with a hingeable cover, a xedelectrode, an inner cover plate, a removable electrode ccmprising aphotographic plate, clamping members and intermediate clamping meansoperatively connecting one of said clamping members with said cover,adapted to clamp the lateral surfaces of said photographic plate onclosure thereof; means attached to said cover adapted to contact saidphotographic plate on closure of said cover, and means for connectingsaid xed electrode and removable electrode in an exterior circuit.

2. A device for the electrolytic treatment of photographic platescomprising a tank having a hingeably mounted cover, a fixed electrodeand a removable electrode mounted within said tank, said fixed electrodecomprising a Zinc plate, and said removable electrode a metallicphotographic plate, means contained within said tank for clamping thelateral surfaces of said removable plate and additional meanscooperating with said clamping means and said cover adapted to operatesaid clamping means on closure of said cover and means in connectionwith said cover to furnish a conductive contact with said plate withclosure of said cover.

3. A device for the electrolytic treatment of metallic photographicplates, comprising a tank having vertical oppositely aligned groovesformed in the side walls thereof, a cover hingedly attached to saidtank, an inner cover plate fitted within said tank and provided with aslotted opening registering with the upper extremity of said verticalgroove and adapted for the reception of a metallic photographic platewhich functions as an electrode, a fixed electrode mounted Within saidtank, means adapted to clamp the lateral surfaces of said photographicplate on closure of the hingeable cover, and contact means adapted toengage the photographic plate on closure of the hinged cover.

4. A device for the electrolytic treatment of a metallic photographicplate, comprising a glass lined tank having a vertical groove formed ineach side wall thereof, a cover hingeably attached to said tank, aninner cover plateV fitted within said tank and provided with a slottedopening registering with the upper extremity of said vertical groovesand adapted for the reception of a metallic photographic plate whichfunctions as an electrode, a fixed electrode mounted within said tankconductively connected to an exterior lead wire, a fixed and ahorizontally movable clamping member mounted Within the tank adjacentthe upper extremity of the photographic plate, said members providedwith adjacent edge plates of conductive material, intermediate meansoperatively connecting the horizontally movable clamping member with thehingeably mounted cover adapted to convert the rotative movement of thecover to horizontal transverse movement of said movable clamping memberto bring both of said clamping members into conductive contact with saidphotographic plate, and a contact member provided with downwardlyprojecting tines attached to the inner surface of said coverconductively connected to an exterior lead wire and adapted to makeconductive contact with the photographic plate and the aforesaidadjacent edge plates when the cover of said tank is closed.

5. A device for the electrolytic treatment of photographic platescomprising a glass lined tank provided with a hingeable cover, a xedelectrode, an inner cover plate of insulating material, a removableelectrode comprising a photographic plate, clamping members adapted toengage the lateral surfaces of said photographic plate, and intermediateclamping means operatively connecting one of said clamping members withsaid cover, adapted to move said clamping' member into engagement withsaid photographic plate on closure thereof; means attached to said coveradapted to make an electrical contact with said photographic plate onclosure of said cover, and means for connecting said fixed electrode andremovable electrode in an exterior circuit.

6. A device for the electrolytic treatment of photographic platescomprising a glass lined tank provided with a hingeable cover, a fixedelectrode, an .inner cover plate of insulating material, a removableelectrode comprising a photographic plate, clamping members providedwith conducting surfaces adapted to engage the lateral surfaces of saidphotographic plate, and intermediate said clamping members with saidcover, adapted to move said clamping member into engagement with saidphotographic plate on closure thereof; means attached to said coveradapted to make ,6 0 clamping means operatively connecting one ofelectrical contact with the conducting surfaces sure thereof; meansattached to said` cover adapted to make an electrical contact with saidphotographic plate on closure of said. cover, and means for connectingsaid xed electrode and removable electrode in an exterior circuit.

JOHN J. BUCHSER.

